Laughter and the Brain

Introduction to PsychologyMay 2009D. Bambic

Have you ever wondered why we laugh? What is laughter anyway? What happens in our body and brain when we

laugh? Can we control laughter? Can we laugh on command? Why do they say “laughter is the best medicine”?

This presentation will answer these questions and examine the pleasure/reward brain circuitry in the act of laughing.

What’s so funny?

Laughter is not the same thing as humour. It is the body’s response to humour (and so

it includes a subjective appreciation of the humour).

Consists of two parts: gestures and sound Fifteen different facial muscles come into

play The larynx half closes, creating the irregular

air intake or the characteristic sound of (gasping) laughter.

Tear ducts can be activated and the person can appear to be gasping for air.

Definition

http://www.pbs.org/saf/1105/video/watchonline.htm

Linguists = laughter is like punctuation because it usually occurs at the end of phrases or during pauses.

Analysis shows that it is very regular in its sound waves, not like speech.

Neurobiologist Robert Provine: sonic structure of laughter consists of variations on a basic form of short, vowel-like notes repeated every 210 milliseconds.

Ha-ha-ha OR ho-h0-ho but not both types

The structure of laughter

The average person laughs approximately 17 times per day.

We are 30 times more likely to laugh in a social situation than by ourselves.

Laughter is an effective way to control group behaviour. Think of how it is used to diffuse tempers and shift the emotional climate of a situation.

Laughter strengthens relationships. Dominant individuals use laughter more

than their subordinates.

Laughter as a social activity

The pattern of brainwave activity in subjects responding to humorous material.

Electroencephalograph (EEG) measures brain activity and researchers saw that the brain produces a regular electrical pattern. Within four-tenths of a second of exposure to something potentially funny, an electrical wave moved through the cerebral cortex, the largest part of the brain. If the wave took a negative charge, laughter resulted. If it maintained a positive charge, no response was given, researchers said.

Gelotology: the study of the brain laughing!

During the experiment, researchers observed the following specific activities:

The left side of the cortex (the layer of cells that covers the entire surface of the forebrain) analyzed the words and structure of the joke.

The brain's large frontal lobe, which is involved in social emotional responses, became very active.

The right hemisphere of the cortex carried out the intellectual analysis required to "get" the joke.

Brainwave activity then spread to the sensory processing area of the occipital lobe (the area on the back of the head that contains the cells that process visual signals).

Stimulation of the motor sections evoked physical responses to the joke.

The limbic system is a network of structures located beneath the cerebral cortex. This system is important because it controls some behaviors that are essential to the life of all mammals such as forming memory and experiencing pleasure.

Can you imagine if people could not do these things?

What would motivate parents to care for offspring?

The limbic system

Limbic system= hippocampus + amygdala (regulates moods and emotions)

The limbic system also controls laughter, friendship, love and affection

Two hunters are out in the woods when one of them collapses. He doesn't seem to be breathing and his eyes are glazed. The other guy takes out his phone and calls the emergency services.

He gasps: "My friend is dead! What can I do?"

The operator says: "Calm down, I can help. First, let's make sure he's dead."

There is a silence, then a gunshot is heard. Back on the phone, the guy says: "OK, now what?"

Voted the world’s funniest joke

reduces pain and allows us to tolerate discomfort.

It reduces blood sugar levels, increasing glucose tolerance in diabetics and non-diabetics alike.

It helps your blood vessels function better. It acts on the inner lining of blood vessels, called the endothelium, causing vessels to relax and expand, increasing blood flow. In other words, it's good for your heart and brain, two organs that require the steady flow of oxygen carried in the blood.

The best medicine

TICKLED WITH YOUR OWN FINGER Here's a challenge. Do you think that you can be tickled

with your own finger if someone else controls its movements? To check this out, you'll need to relax enough so that your partner moves your finger without any resistance. First, remove your shoe and sock. Cross your legs so that your left foot extends horizontally across your right thigh. Have your partner sit on your right side. Let them take your right hand and hold it so that your index finger extends outward. Relax and give up control of your right arm, finger, and hand. Challenge your partner to tickle your exposed arch using your index finger. Can it be done? Even though you are not in control of the movements, does your body have automatic feedback that tells you where and what your body parts are doing?

Tickle Experiment

From the Gazette (May 05/2009) http://

www.montrealgazette.com/Technology/Doug+Collins+master+laughter/1562612/story.html

Mr. Collins is famous for the most contagious laughter in the world.

His story is touching because can bring laughter to everyone despite his own tragedy.

http://www.youtube.com/watch?v=Z4Y4keqTV6w And it is contagious! http://

www.youtube.com/watch?v=p32OC97aNqc&feature=related

Doug Collins: The Master of Laughter

Laugh your pants off and have a great day!